Performed heat check. Checked the electrical, mechanical, safety, and performance of the system. I cleared the condensation drain line and flow tested the drain with two gallons of water. I also treated the drain line. I replaced the air filter with a new Aprilaire 210 filter. Homeowner also asked me to install a new thermostat that she had purchased. I installed the thermostat and function tested the system in heating and cooling. No major issues were found. The system was operational and running at the completion of service.